XFORM.C

/* 
 * (c) Copyright 1993, Silicon Graphics, Inc. 
 * ALL RIGHTS RESERVED  
 * Permission to use, copy, modify, and distribute this software for  
 * any purpose and without fee is hereby granted, provided that the above 
 * copyright notice appear in all copies and that both the copyright notice 
 * and this permission notice appear in supporting documentation, and that  
 * the name of Silicon Graphics, Inc. not be used in advertising 
 * or publicity pertaining to distribution of the software without specific, 
 * written prior permission.  
 * 
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" 
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR 
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON 
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT, 
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY 
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, 
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF 
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN 
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON 
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE 
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE. 
 *  
 * US Government Users Restricted Rights  
 * Use, duplication, or disclosure by the Government is subject to 
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph 
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software 
 * clause at DFARS 252.227-7013 and/or in similar or successor 
 * clauses in the FAR or the DOD or NASA FAR Supplement. 
 * Unpublished-- rights reserved under the copyright laws of the 
 * United States.  Contractor/manufacturer is Silicon Graphics, 
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311. 
 * 
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc. 
 */ 
#include <windows.h> 
#include <math.h> 
#include <stdio.h> 
#include <GL/gl.h> 
#include "3d.h" 
 
#define static 
 
#define STACKDEPTH 10 
 
typedef struct { 
    GLdoublemat[4][4]; 
    GLdoublenorm[3][3]; 
} mat_t; 
 
static mat_t matstack[STACKDEPTH] = { 
    {{{1.0, 0.0, 0.0, 0.0}, 
    {0.0, 1.0, 0.0, 0.0}, 
    {0.0, 0.0, 1.0, 0.0}, 
    {0.0, 0.0, 0.0, 1.0}}, 
    {{1.0, 0.0, 0.0}, 
    {0.0, 1.0, 0.0}, 
    {0.0, 0.0, 1.0}}} 
}; 
static int identitymat = 1; 
 
static int mattop = 0; 
 
void m_xformpt(GLdouble pin[3], GLdouble pout[3],  
    GLdouble nin[3], GLdouble nout[3]) 
{ 
    inti; 
    GLdoubleptemp[3], ntemp[3]; 
    mat_t*m = &matstack[mattop]; 
 
    if (identitymat) { 
for (i = 0; i < 3; i++) { 
    pout[i] = pin[i]; 
    nout[i] = nin[i]; 
} 
return; 
    } 
    for (i = 0; i < 3; i++) { 
ptemp[i] = pin[0]*m->mat[0][i] + 
   pin[1]*m->mat[1][i] + 
   pin[2]*m->mat[2][i] + 
   m->mat[3][i]; 
ntemp[i] = nin[0]*m->norm[0][i] + 
   nin[1]*m->norm[1][i] + 
   nin[2]*m->norm[2][i]; 
    } 
    for (i = 0; i < 3; i++) { 
pout[i] = ptemp[i]; 
nout[i] = ntemp[i]; 
    } 
    normalize(nout); 
} 
 
void m_xformptonly(GLdouble pin[3], GLdouble pout[3]) 
{ 
    inti; 
    GLdoubleptemp[3]; 
    mat_t*m = &matstack[mattop]; 
 
    if (identitymat) { 
for (i = 0; i < 3; i++) { 
    pout[i] = pin[i]; 
} 
return; 
    } 
     for (i = 0; i < 3; i++) { 
ptemp[i] = pin[0]*m->mat[0][i] + 
   pin[1]*m->mat[1][i] + 
   pin[2]*m->mat[2][i] + 
   m->mat[3][i]; 
    } 
    for (i = 0; i < 3; i++) { 
pout[i] = ptemp[i]; 
    } 
} 
 
void m_pushmatrix(void) 
{ 
    if (mattop < STACKDEPTH-1) { 
matstack[mattop+1] = matstack[mattop]; 
mattop++; 
    } else 
error("m_pushmatrix: stack overflow\n"); 
} 
 
void m_popmatrix(void) 
{ 
    if (mattop > 0) 
mattop--; 
    else 
error("m_popmatrix: stack underflow\n"); 
} 
 
void m_translate(GLdouble x, GLdouble y, GLdouble z) 
{ 
    inti; 
    mat_t*m = &matstack[mattop]; 
 
    identitymat = 0; 
    for (i = 0; i < 4; i++) 
m->mat[3][i] = x*m->mat[0][i] + 
 y*m->mat[1][i] + 
 z*m->mat[2][i] + 
 m->mat[3][i]; 
} 
 
void m_scale(GLdouble x, GLdouble y, GLdouble z) 
{ 
    inti; 
    mat_t*m = &matstack[mattop]; 
 
    identitymat = 0; 
    for (i = 0; i < 3; i++) { 
m->mat[0][i] *= x; 
m->mat[1][i] *= y; 
m->mat[2][i] *= z; 
    } 
    for (i = 0; i < 3; i++) { 
m->norm[0][i] /= x; 
m->norm[1][i] /= y; 
m->norm[2][i] /= z; 
    } 
}